Improvement in dumb-waiters



W. F. HOLSKE. Dumb-Waiter.

Patented June I7, 1879.

Nv PETERS, PHoru LITHOGRAPMEK, WASHXNGTON, D Cv UNITED STATES PATENT OFFICE.

WILLIAM F. HOLSKE, OF BROOKLYN, ASSIGNOR TO B. CLARENCE DORSE'IT, OF NEW YORK, N. Y.

IMPROVEMENTIN DUMB-WAIT ERS.

Specification forming part of Letters Patent No. 216,568, dated June 17, 1879 application filed January 15, 1879.

To all whom it may concern:

Be it known that I, WILLIAM F. HOLSKE, of the city of Brooklyn. county of Kings, and State of New York, have invented a new and useful Improvement in Dumb -Waiters, of which the following is a specification.

By this invention the counterweight usually employed in connection with dumb-waiters is dispensed with. The counterbalancing of the platform and load is accomplished by a system of differential pulleys.

Referring to the drawings, Figure l is a front elevation of my improvement. Fig. 2 is a side elevation of the same. Fig. 3 is afront elevation of. the mode of adjusting the rope by means of a pawl and rack. Fig. 4 is afront elevation of the mode of adjustment by means of a weight.

Similar letters in the various figures refer to the same parts.

A and A are differential pulleys of the same sizes, one being permanent, and the other adjustable by means of a screw and nut, the shank sliding in a square socket, thus permitting the length of the rope to be adjusted at pleasure. In the drawings this adjustment is marked G, and shown as part of differential pulley A. b b b b are simply guide-pulleys for the rope E. 00 are also pulleys for the rope I E, and are permanently attached to the platform D. The rope E is an endless one, and runs around the pulleys as follows, viz: Oommencin g at a point, F, the ropeE runs over the guide-pulley b from the right; over the smaller part of the difierential pulley A, also from the right; around the guide-pulley c from the left, and then over the larger part of the differential pulley A from the right; then over the guidepulleys b and b from the right, and over the larger part of the differential pulley A from the left; around the guide-pulley c from the right; then over the smaller part of the differential pulley A from the left, and then over the guide-pulley b from the left to F, the point of beginning. G is the lower portion of the adjustable differential pulley A, which can be either in the shape of a screw and nut, as Gin Fig. 1, arack and pawl, as H in Fig. 3, or a weight, as I in Fig. 4, neither of which modes I claim as my invent-ion.

I do not confine myself in the application of the system of (liiferential pulleys to dumbwaiters to the exact arrangement shown in the accompanying drawings.

What I claim as my invention, and desire to secure by Letters Patent, is-

The system of difl'erential pulleys, one of them being adjustable, in combination with the platform of a dumb-waiter connected with said pulleys by an endless rope or chain, substantially as shown and described.

WM. F. HOLSKE.

Witnesses GEORGE HOFFMAN, FREDERIC M. DEAN. 

